Wash sago gently. Remove excess water. Keep aside for 1 hour. Loosen the sago and break lumps with figures. Sprinkle a handful of water. Keep aside for 1 hour. Loosen as before.
Take in a mixing bowl. Add the peanuts, coconut, cumin seeds, sugar, salt and lime. Mix well with hands or wooden spatula.
Just before serving, heat oil in a non-stick sauce pan, add potatoes and stir fry till tender. Add green chillies and stir. Add sago mixture and stir gently till uniformly mixed. Cover and cook for 5 minutes on very low flame, frequently stir in between.
When the sago grains become transparent and soft, add coriander and mix. Serve immediately, with hot tea or coffee.